Investigations of strain in ZnMgSe/ZnSe microdisks by means of the micro‐Raman imaging

Abstract

AbstractStrain in the semiconductor multilayer structures of lasing devices has an important influence on their optical properties. Micro‐Raman spectroscopy is a suitable technique for non‐destructive direct analysis of the structural properties of semiconductor structures. The strain distribution in ZnMgSe/ZnSe microdisks has been measured by micro‐Raman spectroscopy. The frequency of the ZnSe longitudinal optical phonon shifts about 2.8 cm‐1 towards lower frequencies from the centre to the edge of the disk. In the central region of the disk the ZnSe quantum well and the ZnMgSe barriers are pseudomorphic strained on GaAs while in the free stranding region the ZnSe quantum well is pseudomorphic with the ZnMgSe barriers. Despite the strain relaxation alongthe radial direction of the disk, the microdisk is free of defects as demonstrated by the absence of the transverse optical phonon lines. These findings confirm sufficiently high quality values in such strained microdisk cavities to facilitate their application in optoelectronic devices. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)